CHAPTER 15: Inheritance

Question 1

what are wild types?

Answer 1

normal phenotypes

Question 2

what is the opposite of wild types?

Answer 2

mutant phenotypes

Question 3

what are sex linked genes?

Answer 3

genes located on either sex chromosome

Question 4

how many Y linked genes are there?

Answer 4

78, coding 25 proteins

Question 5

how many X linked genes are there?

Answer 5

1,110

Question 6

what is an inactive X chromosome called?

Answer 6

Barr body

Question 7

what do Barr bodies involve?

Answer 7

histones

Question 8

what is a XIST gene?

Answer 8

X-Inactive Specific Transcript

Question 9

where is a XIST genre only active?

Answer 9

on a inactivated X chromosome.

Question 10

what are linked genes?

Answer 10

genes that are inherited together

Question 11

what is genetic recombination?

Answer 11

an offspring with a mix of traits different from parents

Question 12

offspring that matches 1 parents phenotype is called ___?

Answer 12

parental types

Question 13

offspring with new trait combinations are called ___?

Answer 13

recombinant types

Question 14

What is a genetic map?

Answer 14

an ordered list of genetic loc along chromosome

Question 15

What does random fertilization do?

Answer 15

increases variant combos that can be made

Question 16

What does a genetic map predict?

Answer 16

the farther apart 2 genes are, the higher crossing over/recombination frequency will occur.

Question 17

What is a linkage map?

Answer 17

genetic map based on recombination frequencies

Question 18

What do map units represent?

Answer 18

distance between genes. not precise, only relative distance

Question 19

far apart genes on the same frequency can have ____ recombination frequency.

Answer 19

50%

Question 20

what do large chromosomes tend to lead to?

Answer 20

miscarriages or development disorders

Question 21

what is nondisjunction?

Answer 21

a pair of homologous chromosomes that don’t separate normally during mitosis.

( 1 gamete gets 2 some chromosomes, 1 gets nothing )

Question 22

what is aneuploidy?

Answer 22

when gamete fertilization in nondisjunction occurs

Question 23

what is a monosomic zygote?

Answer 23

it has 1 chromosome copy
(mono = 1)

Question 24

what is a trisomic zygote?

Answer 24

it has 3 copies of chromosome
(tri=3)

Question 25

what is a polyploidy?

Answer 25

organisms that has more than 2 complete chromosome sets?

Question 26

what is a triploidy?

Answer 26

has 3 chromosome sets (3n)

Question 27

what is a tetraploidy?

Answer 27

has 4 chromosome sets (4n)

Question 28

what does deletion do?

Answer 28

removes chromosomal fragment

Question 29

what are the four changes in chromosome structure?

Answer 29

deletion, duplication, inversion, translocation.

Question 30

what does duplicaton do?

Answer 30

repeats a segment

Question 31

what does inversion do?

Answer 31

reverses orientation of segment within a chromosome

Question 32

what does translocation do?

Answer 32

moves segment from one chromosome to another.

Question 33

what causes a variety of aneuploid conditions?

Answer 33

nondisjunction of sex chromosomes

Question 34

what is genetic imprinting?

Answer 34

involves silencing certain genes depending on which parent passed it.

Question 35

what was one of the first discovered imprinted genes?

Answer 35

lgf2

Question 36

what is down syndrome cause by?

Answer 36

three copies of chromosome 21

Question 37

what are histones ?

Answer 37

proteins bounded to X chromosomes + DNA